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Diffstat (limited to 'mit-pthreads/pthreads/pthread_once.c')
| -rw-r--r-- | mit-pthreads/pthreads/pthread_once.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/pthread_once.c b/mit-pthreads/pthreads/pthread_once.c new file mode 100644 index 00000000000..0a3dcd23fae --- /dev/null +++ b/mit-pthreads/pthreads/pthread_once.c @@ -0,0 +1,59 @@ +/* ==== pthread_once.c ======================================================= + * Copyright (c) 1993, 1994 by Chris Provenzano, proven@mit.edu + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Chris Provenzano. + * 4. The name of Chris Provenzano may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Description : pthread_once function. + * + * 1.00 93/12/12 proven + * -Started coding this file. + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include <pthread.h> + +/* ========================================================================== + * pthread_once() + */ +int pthread_once(pthread_once_t *once_control, void (*init_routine)(void)) +{ + /* Check first for speed */ + if (once_control->state == PTHREAD_NEEDS_INIT) { + pthread_mutex_lock(&(once_control->mutex)); + if (once_control->state == PTHREAD_NEEDS_INIT) { + init_routine(); + once_control->state = PTHREAD_DONE_INIT; + } + pthread_mutex_unlock(&(once_control->mutex)); + } + return(OK); +} |